1. Field of the Invention
The invention relates to a fuel cell system that includes a fuel cell, and to a control method for the fuel cell system.
2. Description of Related Art
There is known a fuel cell system that activates a fuel cell after stopping the circulation of a cooling medium in the case where the system is activated below the freezing point (see Japanese Patent Application Publication No. 2003-36874 (JP-A-2003-36874)). This configuration prevents an event in which, at the time of such activation, the very cold cooling medium is sent into an interior of the fuel cell and therefore the internal temperature of the fuel cell becomes excessively low. In this configuration, when the internal temperature of the fuel cell subsequently rises up, the circulation of the cooling medium is started.
However, in the foregoing related art, as the circulation of the cooling medium starts, the temperature near a cooling medium inlet of the fuel cell and the ambient temperature around the cooling medium inlet temporarily drops, so that the product water remaining from before the system is activated (hereinafter, referred to as “remaining water”) sometimes re-freezes. If the remaining water re-freezes, a catalyst layer in the fuel cell may be damaged.